OBD-II Fault Code

B1240: Wiper Washer Rear Pump Relay Circuit Failure

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for B1240.

System family

Body

Manufacturer-specific

Repair category

Electrical circuit / sensor

Use this category to narrow your checks before replacing parts.

Severity

Medium

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What B1240 usually means

Wiper Washer Rear Pump Relay Circuit Failure.

Common symptoms

Body/accessory warning lamp or feature not working

Likely causes

Faulty related sensor/actuator; Wiring or connector issue; Poor ground/power supply; Control module fault is possible but less common

Diagnostic checks

Check related fuses, connectors, grounds and switch/module power supply

Repair guidance

Repair wiring/connector/fuse issues first; Replace the related sensor/actuator only after testing confirms failure; Use OEM service manual for brand-specific procedures

Verification after repair

Operate the affected body/accessory system and rescan

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary; Manufacturer-specific: confirm definition and test steps in the vehicle service manual. A DTC identifies a circuit or system condition, not always the failed part.